1、Designation: F2382 171Standard Test Method forAssessment of Circulating Blood-Contacting Medical DeviceMaterials on Partial Thromboplastin Time (PTT)1This standard is issued under the fixed designation F2382; the number immediately following the designation indicates the year oforiginal adoption or,
2、 in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1NOTECorrected editorially in January 2018.1. Scope1.1 This test method covers the screening
3、 of circulatingblood-contacting device materials for their ability to induceblood coagulation via the intrinsic coagulation pathway. Thisassay should be part of the hemocompatibility evaluation fordevices and materials contacting human blood, as per ANSI/AAMI/ISO 10993-4.1.2 All safety policies and
4、practices shall be observedduring the performance of this test method.1.3 All plasma and any materials that had contact withplasma will be bagged in a biohazard bag, properly labelledwith the contents, and disposed of by appropriate means. Theplasma should be handled at the Biosafety Level 2 as reco
5、m-mended in the Centers for Disease Control/National Institutesof Health Manual Biosafety in Microbiological Laboratories.1.4 The normal pooled human plasma must have testednegative for Hepatitis B (HBV) or Human Immunodeficiency(HIV) viruses. The plasmas should be treated like any patientplasma usi
6、ng standard precautions. The plasma should behandled at the Biosafety Level 2 as recommended in theCenters for Disease Control/National Institutes of HealthManual Biosafety in Microbiological Laboratories.1.5 The values stated in SI units are to be regarded asstandard. No other units of measurement
7、are included in thisstandard.1.6 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety, health, and environmental practices and deter-mine the applicability of regula
8、tory limitations prior to use.1.7 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Org
9、anization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ANSI/AAMI Standard:ANSI/AAMI/ISO 10993-4 Biological Evaluation of MedicalDevicesPart 4: Selection of Tests for Interactions withBlood22.2 Other Document:U.S. Department of Health and Human Services Biosafety inMicrobiolo
10、gical and Biomedical Laboratories (BMBL),5th ed., 199933. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 activatora medical material which demonstrates ashortened clotting time; an initiator of the intrinsic coagulationpathway.3.1.2 partial thromboplastin time (PTT) assaya modif
11、ica-tion of the Activated Partial Thromboplastin Time (APTT)assay; unlike the APTT test, the PTT assay uses reagent (rabbitbrain cephalin) without activating substances such as silica,kaolin, elagic acid. The material being tested acts as theactivator.3.1.3 read timethe time during which data is col
12、lected todetect a clot.3.1.4 blank timea period at the beginning of an assaywhen no data is taken. This is done to eliminate interferencefrom premixing reagents, bubbles, and so forth.3.1.5 equilibration timethe time allowed for the plasmasamples to warm to 37C. The coagulation analyzer can be setto
13、 zero if samples are pre-warmed to this temperature.1This test method is under the jurisdiction of ASTM Committee F04 on Medicaland Surgical Materials and Devices and is the direct responsibility of SubcommitteeF04.16 on Biocompatibility Test Methods.Current edition approved Sept. 1, 2017. Published
14、 September 2017. Originallyapproved in 2004. Last previous edition approved in 2010 as F2382 04(2010).DOI: 10.1520/F2382-17E01.2Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.3The BMBL 5th Edition (December 2009) is avail
15、able from the GovernmentPrinting Office or https:/www.cdc.gov/biosafety/publications/bmbl5/bmbl.pdfCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized
16、principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.13.1.6 duplicate flagthe agreement between the results ofduplicate samp
17、les in percent. For example, if set to “15,” thedifference between the two channels must be less than or equalto 15 %. If the variance in clot times exceeds this percentage,an asterisk “*” will be printed by the average results on thereport.4. Significance and Use4.1 The purpose of this test method
18、is to determine the timecitrated plasma exposed to medical materials takes to form aclot when exposed to a suspension of phospholipid particlesand calcium chloride. In this test method, the test article is theactivator. The PTT assay is a general screening test for amedical materials ability to acti
19、vate the intrinsic coagulationpathway. Material samples that show a shortened PTT areactivators of the intrinsic coagulation pathway.4.2 The test article, reference materials, and controls areexposed to human plasma. The plasma is tested on a coagula-tion device. Each sample tube is assayed in dupli
20、cate. Theresults are reported as a percentage of the negative control.5. Apparatus5.1 Polypropylene Test Tubes with Caps, 12 by 75 mm.5.2 Automatic Pipets and Tips, 100 and 1000 L.5.3 Ice Bath.5.4 Coagulation Analyzer (Siemens BFT II analyzer orother).5.5 Agitating Water Bath, 37 6 2C, capable of 60
21、 rpm.5.6 Coagulation Analyzer Cuvettes, or equivalent for spe-cific analyzer.6. Reagents and Materials6.1 Calcium Chloride, 25 mM.6.2 Citrated Human Blood Plasma, fresh (less than 4 h fromdraw) or freshly-frozen, maintained at minus 80C, pooled.6.3 Lyophilized Rabbit Brain Cephalin (RBC).6.4 Positiv
22、e Reference Material (Optional), see AppendixX1.6.5 Positive Control, glass (Pasteur pipette tips or glassbeads).6.6 Negative Reference Material (e.g. High DensityPolyethylene, HDPE).6.7 Marketed Comparator Device (Optional). A legallymarketed, clinically acceptable device that has similar bloodcont
23、act nature and clinical use as the material/device beinginvestigated.NOTE 1It may be helpful to use a positive reference control material(n=1) per assay to assure continuity between runs.7. Hazards7.1 The human blood plasma should be treated like anypatient plasma using standard precautions. The pla
24、sma shouldbe handled at the Biosafety Level 2 as recommended in the USDepartment of Health and Human Services Biosafety inMicrobiological and Biomedical Laboratories.8. Preparation of Apparatus8.1 Prepare each test article, the negative referencematerials, marketed comparator device (if used) and co
25、ntrols intriplicate. If a positive reference control material is used, asingle replicate is acceptable. All samples are prepared basedon a ratio of either 4 or, preferably 6 cm2of material to 1 mLplasma and placed into polypropylene tubes. For devicetesting, if test sample quantity allows, use three
26、 separatedevices; otherwise, take three representative samples from onedevice.8.2 Label duplicate polypropylene tubes and place in the icebath.8.3 Turn on the coagulation analyzer and allow it to warmup to 37 6 2C and equilibrate for at least 10 min.8.4 Program the analyzer to test under the APTT fu
27、nctionwith an equilibration time of 60 s, activation time of 120 s, a| blank time of 14 s, and a read time of 286 s.8.5 Pre-warm analysis cuvettes (or cups, depending onanalyzer selected) at 37 6 2C.8.6 Pre-warm calcium chloride at 37 6 2C.8.7 Rabbit Brain Cephalin (RBC) Preparation:8.7.1 Allow the
28、RBC to come to room temperature.8.7.2 Reconstitute the RBC as indicated by the RBC reagentmanufacturer.8.7.3 Place in an agitating water bath set at 37 6 2C and 60rpm for 15 min to ensure complete rehydration of contents.8.7.4 Vortex 15 s after rehydration is complete.8.7.5 Place at 37 6 2C.8.8 If u
29、sing frozen blood plasma, quick thaw the plasma at37 6 2C and place on ice immediately.9. Procedure9.1 The test material(s), reference material(s), marketedcomparator device (if used) and controls are placed intopolypropylene tubes and exposed to the appropriate quantity ofplasma, based on a ratio o
30、f 4 cm2, or preferably 6 cm2ofmaterial to 1 mL plasma. The negative control is a polypro-pylene tube with 1 mL of plasma, without additional material.9.2 The samples are exposed to the plasma for 15 6 1 minina376 2C agitating water bath at 60 rpm.9.3 After 15 min of incubation, the tubes are immedia
31、telyplaced into the ice bath and immediately transferred intopre chilled new polypropylene tubes.9.4 Vortex each sample 15 s before each use/run.9.5 Avoiding bubbles, transfer 100 L of the plasma intopre-warmed cuvettes and allow the plasma to equilibrate for 60sat376 2C.9.6 To each cuvette/cup, add
32、 100 L warmed RBCpreparation, initiating the 2 min activation step. (Invert RBC tomix prior to each use.)9.7 After activation, add 100 L warmed 25 mM calciumchloride to each cuvette.F2382 17129.8 Allow the analyzer to read the sample for the formationof clots (up to 5 min).9.9 Record the clotting ti
33、me (seconds) for each sample, aswell as the average clotting time of the duplicate samples.NOTE 2The volume of plasma, RBC reagent, and calcium chlorideneeded for the clotting time measurement may vary with differentanticoagulation analyzers. It is acceptable to use a plasma volume that isspecific t
34、o the coagulation analyzer used, as long as the plasma to reagentratio remains 1:1.10. Calculation or Interpretation of Results10.1 Calculate the test sample result (% negative control)for test material, reference, and positive control sample mean.% negative control5 (1)Average clotting time s! of s
35、ampleAverage clotting time s! of negative control3 10010.2 Statistical Analysis of Results:10.2.1 The mean and standard deviation for each group ofplasma: test article, negative control, positive control, andpositive and/or reference material controls are calculated.10.2.2 To stabilize the data vari
36、ation, the natural log trans-formation is applied to all responses. The log transformedvalues for test article, negative control, positive control,negative and/or positive reference material, marketed compara-tor device results are compared to each other with Analysis ofVariance (ANOVA) including po
37、st-hoc pairwise comparisonssuch as a Tukey or Newman-Keuls test.10.2.3 Differences shall be considered statistically signifi-cant if the p-value is less than 0.05. The test article isconsidered to pass the PTT test if there is no statisticaldifference between the test article and the negative contro
38、l(untreated plasma) or the negative reference material control. Ifthe test article result is statistically significantly lower than thenegative control (untreated plasma) or negative referencematerial control, a comparison between the test article and amarketed comparator device would help to determ
39、ine whetherthe test device/material is likely to be clinically acceptable ornot.10.2.4 The positive control and the positive reference ma-terial control (if used) results, expressed as % negative control(untreated plasma), must be 80%. If the assay does not meet thisspecification, the experiment is
40、to be repeated until the controlsmeet these specifications.10.2.5 The Coefficient of Variation (CV) between the dupli-cates for each sample must be 15 %. The duplicates of eachtest article sample are averaged and one value is reported as theclotting time. This results in three clotting time values f
41、or eachtest article. The three values are then averaged to report a finalaverage clotting time of the test article. The values for each testarticle sample must be within 625 % of this average. If thevalues are greater than 25 % of the average of the run, theexperiment needs to be repeated.11. Precis
42、ion and Bias11.1 The precision and bias of this test method has not yetbeen determined.12. Keywords12.1 blood coagulation; blood compatibility; partial throm-boplastin time; PTTANNEX(Mandatory Information)A1. VENDOR INFORMATIONA1.1 Rabbit Brain Cephalin (RBC)Bio/Data,4or equiva-lent vendor.A1.2 Coag
43、ulation AnalyzerAble to reliably detect clotformation, with a maximum clot detection time greater than300 seconds.A1.3 Reference Control MaterialNatural latex tubing(Fisher Scientific5and McMaster-Carr6or equivalent vendor)or black rubber stopper (Fisher5or equivalent vendor). Alter-nate reference m
44、aterials may be selected, once they havedemonstrated a consistent, thrombogenic response. More thanone reference material may be used.4Available from Bio/Data, 155 Gilbraltar Rd., Horsham, PA 19044.5Available from Fisher Scientific, 300 Industry Dr., Pittsburgh, PA 15275.6Available from McMaster-Car
45、r, 200 New Canton Way, Robbinsville, NJ,08691.F2382 1713APPENDIX(Nonmandatory Information)X1. RATIONALEX1.1 This test method allows assessment of medical devicematerials ability to induce blood coagulation via the intrinsiccoagulation pathway. It should be part of the hemocompatibil-ity evaluation f
46、or devices and materials contacting humanblood.REFERENCES(1) Sawyer, A., “In Vitro Hemocompatibility Screening Method forBiomaterials,” World Congress for Biomaterials MeetingTransactions, 1992, p. 669.(2) U.S. Department of Health and Human Services Biosafety in Micro-biological and Biomedical Labo
47、ratories (BMBL), 5th ed., 2009.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof i
48、nfringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this sta
49、ndard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (sin
